1. Field of the Invention
The present invention relates to a display device such as a liquid crystal display device used for information apparatus, home electrical appliances, and the like.
2. Description of the Related Art
With a recent growth of an information-oriented society, liquid crystal display devices have attracted increasing attention as display devices to be incorporated in information apparatus and home electrical appliances. This is because liquid crystal display devices are advantageous in that they are thin, light in weight, and operable with low power consumption.
FIG. 7 shows a conventional liquid crystal display device, and FIG. 8 shows a sectional view taken along line C-C' of FIG. 7. The illustrated conventional liquid crystal device includes a liquid crystal panel 1 and a circuit board provided at the periphery of the liquid crystal panel 1 for driving pixels. The liquid crystal panel 1 includes a pair of substrates 1a and 1b each having an electrode and a liquid crystal layer interposed between the pair of substrates 1a and 1b. The circuit board includes a plurality of tape carrier packages (TCPs) 12 arranged in parallel, each of which includes an integrated circuit (IC) 3 for driving lines and pixels mounted on a flexible base. An output terminal group of each TCP is connected with the liquid crystal panel 1 via an anisotropic conductive film (ACF) 7, while an input terminal group thereof is connected with a printed board 4 via an ACF or a solder 8. The liquid crystal panel 1 is fixed to a chassis 5 with ribs 6a provided at the four corners of the liquid crystal panel 1.
In order to realize further enhanced image quality and fineness for the liquid crystal display devices, the demand for reductions in pixel size has all the more increased. As the size of the pixels is reduced, the pixel pitch also needs to be smaller. This makes it extremely difficult to connect the liquid crystal panel 1 with the circuit board (i.e., the TCPs and the like) disposed at the periphery of the liquid crystal panel 1. More specifically, as the pixel pitch of the liquid crystal panel 1 becomes smaller, the area of pixels which can be driven by one IC 3 becomes smaller, and thus the width of the input terminal group of the TCP 12 which includes the IC 3 is smaller. As the width of the input terminal group of the TCP 12 is smaller, the area of the TCP 12 which is in contact with the ACF or solder 8 is smaller. This makes it difficult to connect the TCP 12 with the printed board 4.
In order to overcome the above problem, Japanese Laid-Open Publication No. 5-173166 discloses a liquid crystal display device as shown in FIG. 9. In this conventional liquid crystal display device, the width of the input terminal side of each of TCPs 30a and 30b is different from the width of the output terminal side thereof. Moreover, the input terminal sides of the adjacent TCPs 30a and 30b are alternately shifted from each other, forming a zig-zag array. In this way, the width of the input terminal groups of the TCPs 30a and 30b can be made large compared with the width of the TCPs 12 of the uniform shape arranged in a line as shown in FIG. 7. This facilitates the connection of the TCPs 30a and 30b with the printed board 4 via the ACF or solder 8.
However, the conventional liquid crystal display device disclosed in the above-mentioned Japanese Laid-Open Publication No. 5-173166 has the following problem. Since two or more different shapes of TCPs are used, the process for connecting the TCPs is extremely complicated and troublesome. Two or more types of molds are also required to form these different shapes of TCPs.
In view of the foregoing, the objective of the present invention is to provide a display device where the connection between the input terminal group of the TCP and the printed circuit board is prevented from being easily disconnected and thus warping of a display panel is prevented.